Implement a ‘bank’ class. The bank should keep track of the account balances for different accounts designated by numeric identifiers. It should support the following operations: deposit/withdraw to a single account, transfer between two accounts, and calculate the total amount of money in the bank. Opening a new account should be done by depositing or transferring money to a previously-unused account ID. Accounts cannot have negative balances. Regulations also state that no account may hold more than $100M.
